package JCT_Chapter_03;
import java.util.*;
/**
 * This program demonsdtrates array manipulation
 */
public class LotteryDrawing {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        // 输入需要选取的数字个数
        System.out.print("How many numbers do you need to draw?");
        int k = in.nextInt();
        // 输入最大数字个数
        System.out.print("What is the highest number you can draw?");
        int n = in.nextInt();
        // fill an array with numbers 1,2,3,4...n
        int[] numbers = new int[n];
        for(int i = 0; i < numbers.length; i++) {
            numbers[i] = i+1;
        }
        // draw  k numbers and put them into a second  array
        int[] result = new int[k];
        for (int i = 0; i < result.length; i++ ) {
            // make a random index between  0 and n-1
            int r = (int)(Math.random() * n);
            // pick the element at the random location
            result[i] = numbers[r];
            // move the last element into the random location
            numbers[r] = numbers[n-1];
            n--;
        }
        // print the stored array
        Arrays.sort(result);
        System.out.println("Bet the following combination. It'll make you rich!");
        for(int r : result) {
            System.out.print(r + " ");
        }
        System.out.println();
        System.out.print(Arrays.toString(result));
    }
}
